Concrete arch for sidewalks and over areas



( 0 Model.)

G. GOODMAN.

CONCRETE ARCH FOR SIDE WALKS ANDOVER AREAS.

No. 269,280. Patented De0.19,1882.

Jay-J N. PUENS PMQUMPW \Viullingm ILL UNITED STATES PATENT @EETEE.

GEORGE GOODMAN, OF SAN FRANCISCO, CALIFORNIA.

CONCRETE ARCH FOR SIDEWALKS AND OVER AREAS.

SPECIFICATION formingpart of Letters Patent No. 269,280, dated December 19, 1882. Application nieu August 10, 1882. (No model.)

To all whom it may concern Be it known that I, GEORGE GOODMAN, of the city and county of San Francisco, State of California, have invented an Improvement in ConcreteArchesfor Sidewalks andOverAreas, &c.; and I hereby declare the following to be a lull, clear, and exact description thereof, suflicient to enable any person skilled in the art to which my invention belongs to make and use the same, reference being bad to the accompanying drawings, forming a part of this specification.

My invention relates to the construction of the arches, and also to the construction of the joints between the ends of a series of arches, and also between the ends of single arch es and the abutments, of whatever kind they may be, against which the arches rest.

Most plastic material of which concrete and artificial-stone arches are made will, in course of time,-shrink to slight extent, and thereby will often open the perpendicular joints at the ends of the arches sufficiently to allow water to leak through the joints into the room below.

One principal object of my invention is to remedy this evil.

In the drawings, Figure 1. is a longitudinal section of my improved arches A, and also shows transverse sections of the supportingbeams I) and a transverse section of the line of the joints 0 between the ends of the arches, which joint is inpart perpendicularand in part horizontal. Fig. 2 shows a corresponding section otconcrete and artificial-stone arches, supporting-beams,and filling over the haunches of the arches, as they have heretofore been constructed.

In Fig. 2, (1 represents the arches, c the sup porting-beams, and f the filling over the haunches ot' the arches. The fillingfhas been made over the haunches of the arches for the purpose of giving an even grade to the surface of the pavement in which the arches were used. When the fillingf has been made of concrete or plastic material, so as to make it form a solid part of the pavement, it has been liable to crack irregularly above the supporting-beams, on account of the shrinkage of the material, and thus cause leaking. When the fillingfhas been made of substances other than concrete or plastic material which will turn to artificial stone, the pavements have often been I leaky, and possessed less solidity and strength than when such concrete and plastic materials were used.

In my invention I make the entire arch of concrete or other similar material which sets and hardens into artificial stone. I form the arches with the material whileit isin aplastic state. I make the upper surface level by increasing the thickness of the haunches as they extend from the crown ofeach arch to the ends thereof. In consequence of this thickening of the haunches of the arches they extend a considerable distance above the supporting-beams along the line where the end of each arch meets the end of the adjoining arch, as shown in Fig. 1 of the drawings.

In order to prevent any irregular cracking of the material of the arches on account of shrinkage, I make the arches separated from each other, so that there will be a joint between the ends of the adjoining arches, which joint will be non-adhering or so nearly non-adhering that it will open when the material shrinks, and thus localize between the ends of the arches the vacant space which the shrinkage of the material creates. This prevents the material from cracking irregularly, or in places where cracking would weaken or otherwise injure the structure.

In order to prevent any leakage through the jointsbetween the endsof the arches when such joints open from shrinkage or other cause, I form a lower ledge across the end of one arch and a corresponding upper ledge across the end of the adjoining arch, as shown in Fig. 1. A rabbet is thus made and a joint formed, which jointin'ordinary cases will extend downward from the surface of the pavement about three inches, and then extend horizontally in one direction or the other about two inches, and thence downward through the material to the top of the supporting-beam underneath. The horizontal part of the joint thus formed will not open when the material shrinks, however much such shrinkage may draw the vertical parts of the joint apart. I make the same kind of haunch, ledges, and joint when the end of an arch joins an abutment other than the end of an adjoining arch.

When the concrete material of which the arches are made is used in a very soft or plastic condition there is danger of the ends of the adjoining arches adhering together, so as to partially destroy the division between them, which it is desirable to maintain at the joints in order to prevent irregular cracking, which otherwise is liable to occur as the result of the shrinkage of the material. To avoid the danger of such adherence,I interposea single layer of tin-foil or other similar substance in the joint between the two arches. The tin-foil secures a sure division at the joint without interferin g with its water-tight qualities. In many cases the tin-foil will not be necessary, especiallyif the first arch is well set and hardened before the second arch is formed against it.

Arches thus formed possess more than ordinary strength, are water-tight, and are safe againstthe danger ofsubsequentinjuries which result from the shrinkage of the material used in concrete and other artificial-stone arches as they are now constructed, and also furnish a level surface for the pavement in which they are used.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

A concrete arch having thickened haunches resting on the upper surfaces and sides of the girder, and provided with the rabbeted joint 0, substantially as set forth.

In witness whereof I hereunto set my hand. 0

GEORGE GOODMAN. Witnesses:

S. H. NoURsE, Jos. A. BAYLESS. 

